PAFAH1B3 is a KLF9 target gene that promotes proliferation and metastasis in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human malignancies. Uncontrolled cell proliferation, invasion and migration of pancreatic cancer cells are the fundamental causes of death in PDAC patients. Our previous studies showed that KLF9 inhibits the proliferation, invasion and migration of pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In this study, we found that platelet-activating factor acetylhydrolase IB3 (PAFAH1B3) is highly expressed in pancreatic cancer tissues and cells. In vitro and in vivo studies showed that overexpression of PAFAH1B3 promoted the proliferation and invasion of pancreatic cancer cells, while downregulation of PAFAH1B3 inhibited these processes. We found that KLF9 expression is negatively correlated with PAFAH1B3 expression in pancreatic cancer tissues and cells. Western blotting revealed that KLF9 negatively regulates the expression of PAFAH1B3 in pancreatic cancer tissues and cells. Rescue experiments showed that overexpression of PAFAH1B3 could partially attenuate the suppression of pancreatic cancer cell proliferation, invasion and migration induced by KLF9 overexpression. Finally, chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were carried out, and the results showed that KLF9 directly binds to the promoter of PAFAH1B3 and inhibits its transcriptional activity. In conclusion, our study indicated that KLF9 can inhibit the proliferation, invasion, migration and metastasis of pancreatic cancer cells by inhibiting PAFAH1B3.

Molecular mechanism of dynein-dynactin complex assembly by LIS1.

Cytoplasmic dynein is a microtubule motor vital for cellular organization and division. It functions as a ~4-megadalton complex containing its cofactor dynactin and a cargo-specific coiled-coil adaptor. However, how dynein and dynactin recognize diverse adaptors, how they interact with each other during complex formation, and the role of critical regulators such as lissencephaly-1 (LIS1) protein (LIS1) remain unclear. In this study, we determined the cryo-electron microscopy structure of dynein-dynactin on microtubules with LIS1 and the lysosomal adaptor JIP3. This structure reveals the molecular basis of interactions occurring during dynein activation. We show how JIP3 activates dynein despite its atypical architecture. Unexpectedly, LIS1 binds dynactin's p150 subunit, tethering it along the length of dynein. Our data suggest that LIS1 and p150 constrain dynein-dynactin to ensure efficient complex formation.

The value of Lp(a) and TG/HDLC in peripheral blood to assess the stability of carotid plaque in patients with ischemic stroke.

OBJECTIVE: The objective of this study was to investigate the relationship between lipoprotein (a) (Lp(a)), triglyceride/high-density lipoprotein cholesterol (TG/HDL-C), and the stability of carotid atherosclerotic plaque in patients with acute ischemic stroke. METHODS: A total of 142 patients with acute ischemic stroke were selected and divided into group A (59 cases of stable plaque formation) and group B (83 cases of unstable plaque formation) according to the characteristics of carotid artery plaque formation detected by carotid color Doppler ultrasound. The serum Lp(a), lipid metabolism indexes, peripheral blood routine indexes, and related serum inflammatory factors indexes were compared between the two groups. Receiver operating characteristic curve and multivariate logistic regression model were used to analyze the relationship between each index and the formation of carotid unstable plaque. RESULTS: There were no significant differences in serum total cholesterol (TC), HDL-C, and low-density lipoprotein cholesterol (LDL-C) between groups A and B (p > .05). The values of Lp(a), TG, and TG/HDL-C in group B were higher than those in group A, and the differences were statistically significant (p < .05). There were no significant differences in serum TC, HDL-C, and LDL-C between groups A and B (p > .05). The values of Lp(a), TG, and TG/HDL-C in group B were higher than those in group A, and the differences were statistically significant (p < .05). The values of HBA1C, Lp-PLA2, CRP, CysC, Hcy, TNF-α, neutrophils, and NLR in group B were higher than those in group A, and the differences were statistically significant (p < .05). There was no significant difference in FPG, systolic blood pressure, diastolic blood pressure, Hb, white blood cells, platelets, and lymphocytes between groups A and B (p > .05). The results of logistic regression model showed that the increase of Lp(a), TG/HDL-C, HBA1C, Lp-PLA2, CRP, CysC, Hcy, and NLR could increase the risk of carotid artery unstable plaque in patients with ischemic stroke (p < .05). CONCLUSION: Lp(a) and TG/HDL-C have certain value in evaluating the stability of carotid atherosclerotic plaque in patients with acute ischemic stroke, and the increased levels of LP (a) and TG/HDL-C will significantly increase the risk of carotid unstable plaque in patients.

Role of uranium toxicity and uranium-induced oxidative stress in advancing kidney injury and endothelial inflammation in rats.

OBJECTIVE: Uranium exposure may cause serious pathological injury to the body, which is attributed to oxidative stress and inflammation. However, the pathogenesis of uranium toxicity has not been clarified. Here, we evaluated the level of oxidative stress to determine the relationship between uranium exposure, nephrotoxic oxidative stress, and endothelial inflammation. METHODS: Forty male Sprague-Dawley rats were divided into three experimental groups (U-24h, U-48h, and U-72h) and one control group. The three experimental groups were intraperitoneally injected with 2.0 mg/kg uranyl acetate, and tissue and serum samples were collected after 24, 48, and 72 h, respectively, whereas the control group was intraperitoneally injected with 1.0 ml/kg normal saline and samples were collected after 24 h. Then, we observed changes in the uranium levels and oxidative stress parameters, including the total oxidative state (TOS), total antioxidant state (TAS), and oxidative stress index (OSI) in kidney tissue and serum. We also detected the markers of kidney injury, namely urea (Ure), creatine (Cre), cystatin C (CysC), and neutrophil gelatinase-associated lipocalin (NGAL). The endothelial inflammatory markers, namely C-reactive protein (CRP), lipoprotein phospholipase A2 (Lp-PLA2), and homocysteine (Hcy), were also quantified. Finally, we analyzed the relationship among these parameters. RESULTS: TOS (z = 3.949; P < 0.001), OSI (z = 5.576; P < 0.001), Ure (z = 3.559; P < 0.001), Cre (z = 3.476; P < 0.001), CysC (z = 4.052; P < 0.001), NGAL (z = 3.661; P < 0.001), and CRP (z = 5.286; P < 0.001) gradually increased after uranium exposure, whereas TAS (z = -3.823; P < 0.001), tissue U (z = -2.736; P = 0.001), Hcy (z = -2.794; P = 0.005), and Lp-PLA2 (z = -4.515; P < 0.001) gradually decreased. The serum U level showed a V-shape change (z = -1.655; P = 0.094). The uranium levels in the kidney tissue and serum were positively correlated with TOS (r = 0.440 and 0.424; P = 0.005 and 0.007) and OSI (r = 0.389 and 0.449; P = 0.013 and 0.004); however, serum U levels were negatively correlated with TAS (r = -0.349; P = 0.027). Partial correlation analysis revealed that NGAL was closely correlated to tissue U (rpartial = 0.455; P = 0.003), CysC was closely correlated to serum U (rpartial = 0.501; P = 0.001), and Lp-PLA2 was closely correlated to TOS (rpartial = 0.391; P = 0.014), TAS (rpartial = 0.569; P < 0.001), and OSI (rpartial = -0.494; P = 0.001). Pearson correlation analysis indicated that the Hcy levels were negatively correlated with tissue U (r = -0.344; P = 0.030) and positively correlated with TAS (r = 0.396; P = 0.011). CONCLUSION: The uranium-induced oxidative injury may be mainly reflected in enhanced endothelial inflammation, and the direct chemical toxicity of uranium plays an important role in the process of kidney injury, especially in renal tubular injury. In addition, CysC may be a sensitive marker reflecting the nephrotoxicity of uranium; however, Hcy is not suitable for evaluating short-term endothelial inflammation involving oxidative stress.

Lipoprotein-associated phospholipase A2 predicts cardiovascular death in patients on maintenance hemodialysis: a 7-year prospective cohort study.

BACKGROUND: Cardiovascular diseases (CVD) is the leading cause of death among maintenance hemodialysis patients, with dyslipidemia being a prevalent complication. The paradoxical relationship between cardiovascular outcomes and established lipid risk markers, such as low-density lipoprotein cholesterol (LDL-C), complicates lipid management in this population. This study investigated Lipoprotein-associated phospholipase A2 (Lp-PLA2), an emerging biomarker known for its proinflammatory and proatherogenic properties, as a potential cardiovascular prognostic marker in this cohort. In this context, the association between Lp-PLA2 levels and cardiovascular outcomes was evaluated, with the aim to facilitate more accurate stratification and identification of high-risk individuals. METHODS: From August 2013 to January 2014, 361 hemodialysis patients were prospectively enrolled. Lp-PLA2 activity and laboratory measures at baseline were quantified. Comorbidities and medications were recorded. All patients were followed until the end of April, 2022. The individual and combined effects of Lp-PLA2 activity and LDL-C on patient outcomes were examined. The association between Lp-PLA2 activity and all-cause mortality, cardiovascular mortality, and major adverse cardiovascular events (MACEs) was analyzed. RESULTS: The median Lp-PLA2 activity was 481.2 U/L. In subjects with Lp-PLA2 activity over 481.2 U/L, significantly higher total cholesterol (4.89 vs. 3.98 mmol/L; P < 0.001), LDL-C (3.06 vs. 2.22 mmol/L; P < 0.001), and apolipoprotein B (0.95 vs. 0.75 mmol/L; P < 0.001) were observed. Over a median follow-up of 78.1 months, 182 patients died, with 77 cases identified as cardiovascular death, 88 MACEs happened. Cardiovascular mortality and MACEs, but not all-cause mortality, were significantly increased in the high Lp-PLA2 group. Cox regression analyses showed that high Lp-PLA2 activity was associated with cardiovascular mortality and MACE occurrence. After comprehensive adjustment, high Lp-PLA2 activity was independently associated with cardiovascular mortality(as a dichotomous variable: HR:2.57, 95%CI:1.58,4.18, P < 0.001; as a continuous variable: HR:1.25, 95%CI:1.10,1.41, P = 0.001) and MACEs(as a dichotomous variable: HR:2.17, 95%CI:1.39,3.40, P = 0.001; as a continuous variable: HR:1.20, 95%CI:1.07,1.36, P = 0.002). When participants were grouped by median Lp-PLA2 activity and LDL-C values, those with high Lp-PLA2 and low LDL-C had the highest CV mortality. The addition of Lp-PLA2 significantly improved reclassification (as a dichotomous variable NRI = 42.51%, 95%CI: 5.0%,61.33%; as a continuous variable, NRI = 33.32%, 95% CI: 7.47%,56.21%). CONCLUSIONS: High Lp-PLA2 activity is an independent risk factor for cardiovascular mortality and MACEs occurrence in patients on hemodialysis. The combined measures of Lp-PLA2 and LDL-C help to identify individuals with a higher risk of cardiovascular death.

Bioinformatics Analysis Identifies PLA2G7 as a Key Antigen-Presenting Prognostic Related Gene Promoting Hepatocellular Carcinoma through the STAT1/PD-L1 Axis.

BACKGROUND: Antigen presentation may be an important factor contributing to immune evasion in cancer. This study investigated antigen-presenting prognostic related genes (APPGs) and their potential mechanisms in hepatocellular carcinoma (HCC). METHODS: We constructed a score built upon the core APPGs (APP.Score) through nonnegative matrix factorization (NMF) clustering, weighted gene co-expression network analysis (WGCNA), random forest (RF), and least absolute shrinkage and selection operator (LASSO) methods. We also compared the clinical and molecular characteristics of different APP.Score. Furthermore, in vitro experiments were conducted to validate the expression of core APPGs and investigate the effects of phospholipase A2, group 7 (PLA2G7) knockdown on HCC cell development and programmed death-ligand 1 (PD-L1) expression. RESULTS: APP.Score was positively correlated with immune cell infiltration and levels of immune checkpoint inhibitor-related genes, and negatively correlated with overall survival (OS). The area under the curve values were 0.734, 0.747, and 0.679 for survival periods of 1, 2, and 3 years, respectively, indicating that APP.Score could be an independent prognostic factor for patients with HCC. OS of the high expression group of these genes, including PLA2G7, musculin, heat shock protein family A, secreted phosphoprotein 1, and neutrophil cytosolic factor 2 (NCF2) was lower than that of their low expression group. Moreover, the upregulation of key components of APPGs, except NCF2, was observed in HCC. The inhibition of PLA2G7 suppressed HCC progression and reduced PD-L1 and phosphorylated signal transducer and activator of transcription 1 (p-STAT1)/STAT1 levels in HepG2 and Huh-7 cells. Remarkably, the decrease in PD-L1 expression caused by PLA2G7 silencing was reversed upon treatment with a STAT1 activator. CONCLUSION: The results of this study show that APP.Score could be an independent prognostic factor for patients with HCC, and that PLA2G7 silencing inhibits cancer cell development and PD-L1 expression. We provide a new perspective and potential target for immune research on antigen presentation in HCC.

Inhibiting PLA2G7 reverses the immunosuppressive function of intratumoral macrophages and augments immunotherapy response in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is an exceptionally immunosuppressive malignancy characterized by limited treatment options and a dismal prognosis. Macrophages constitute the primary and heterogeneous immune cell population within the HCC microenvironment. Our objective is to identify distinct subsets of macrophages implicated in the progression of HCC and their resistance to immunotherapy. METHODS: Intratumoral macrophage-specific marker genes were identified via single-cell RNA sequencing analyses. The clinical relevance of phospholipase A2 Group VII (PLA2G7), a pivotal enzyme in phospholipid metabolism, was assessed in patients with HCC through immunohistochemistry and immunofluorescence. Flow cytometry and an in vitro co-culture system were used to elucidate the specific role of PLA2G7 in macrophages. Orthotopic and subcutaneous HCC mouse models were employed to evaluate the potential of the PLA2G7 inhibitor in complementing immune checkpoint blockade (ICB) therapy. RESULTS: Single-cell RNA sequencing analyses disclosed predominant PLA2G7 expression in intratumoral macrophages within the HCC microenvironment. The macrophage-specific PLA2G7 was significantly correlated with poorer prognosis and immunotherapy resistance in patients with HCC. PLA2G7high macrophages represent a highly immunosuppressive subset and impede CD8 T-cell activation. Pharmacological inhibition of PLA2G7 by darapladib improved the therapeutic efficacy of anti-programmed cell death protein 1 antibodies in the HCC mouse models. CONCLUSIONS: Macrophage-specific PLA2G7 serves as a novel biomarker capable of prognosticating immunotherapy responsiveness and inhibiting PLA2G7 has the potential to enhance the efficacy of ICB therapy for HCC.

Associations between healthy food groups and platelet-activating factor, lipoprotein-associated phospholipase A2 and C-reactive protein: a cross-sectional study.

PURPOSE: To investigate the association between pro-inflammatory markers platelet-activating factor (PAF), lipoprotein-associated phospholipase A2 (Lp-PLA2), hsCRP, and intake of core food groups including fruit, cruciferous and other vegetables, grains, meat and poultry, fish and seafood, nuts and legumes, and dairy. METHODS: A cross-sectional study was conducted. 100 adults (49 ± 13 years, 31% male) with variable cardiovascular disease risk were recruited. Data were collected in 2021 and 2022. Fasting PAF, Lp-PLA2 activity, hsCRP and usual dietary intake (via a validated food frequency questionnaire) were measured. Intake of foods were converted into serves and classified into food groups. Correlations and multiple regressions were performed with adjustment for confounders. RESULTS: A one-serve increase in cruciferous vegetables per day was associated with 20-24% lower PAF levels. An increase of one serve per day of nuts and legumes was associated with 40% lower hsCRP levels. There were small correlations with PAF and Lp-PLA2 and cheese, however, these were not significant at the Bonferroni-adjusted P < 0.005 level. CONCLUSION: The lack of associations between PAF and Lp-PLA2 and other healthy foods may be due to confounding by COVID-19 infection and vaccination programs which prevents any firm conclusion on the relationship between PAF, Lp-PLA2 and food groups. Future research should aim to examine the relationship with these novel markers and healthy food groups in a non-pandemic setting.

Research Advance of Chinese Medicine in Treating Atherosclerosis: Focus on Lipoprotein-Associated Phospholipase A2.

As a serious cardiovascular disease, atherosclerosis (AS) causes chronic inflammation and oxidative stress in the body and poses a threat to human health. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a member of the phospholipase A2 (PLA2) family, and its elevated levels have been shown to contribute to AS. Lp-PLA2 is closely related to a variety of lipoproteins, and its role in promoting inflammatory responses and oxidative stress in AS is mainly achieved by hydrolyzing oxidized phosphatidylcholine (oxPC) to produce lysophosphatidylcholine (lysoPC). Moreover, macrophage apoptosis within plaque is promoted by localized Lp-PLA2 which also promotes plaque instability. This paper reviews those researches of Chinese medicine in treating AS via reducing Lp-PLA2 levels to guide future experimental studies and clinical applications related to AS.

Nde1 promotes Lis1-mediated activation of dynein.

Cytoplasmic dynein drives the motility and force generation functions towards the microtubule minus end. The assembly of dynein with dynactin and a cargo adaptor in an active transport complex is facilitated by Lis1 and Nde1/Ndel1. Recent studies proposed that Lis1 relieves dynein from its autoinhibited conformation, but the physiological function of Nde1/Ndel1 remains elusive. Here, we investigate how human Nde1 and Lis1 regulate the assembly and subsequent motility of mammalian dynein using in vitro reconstitution and single molecule imaging. We find that Nde1 recruits Lis1 to autoinhibited dynein and promotes Lis1-mediated assembly of dynein-dynactin adaptor complexes. Nde1 can compete with the α2 subunit of platelet activator factor acetylhydrolase 1B (PAF-AH1B) for the binding of Lis1, which suggests that Nde1 may disrupt PAF-AH1B recruitment of Lis1 as a noncatalytic subunit, thus promoting Lis1 binding to dynein. Before the initiation of motility, the association of dynactin with dynein triggers the dissociation of Nde1 from dynein by competing against Nde1 binding to the dynein intermediate chain. Our results provide a mechanistic explanation for how Nde1 and Lis1 synergistically activate the dynein transport machinery.

The value of serum lipoprotein-associated phospholipase A2, ischemia-modified albumin, and cystatin C in predicting coronary heart disease risk: a single center retrospective cohort study.

OBJECTIVE: This study aims to explore the value of serum lipoprotein-associated phospholipase A2 (Lp-PLA2), ischemia-modified albumin (IMA), and cystatin C (Cys-C) in predicting the risk of coronary heart disease (CHD). PATIENTS AND METHODS: Clinical data from 104 CHD patients admitted to our hospital from January 2020 to December 2022 were analyzed. Of them, 31 patients had stable angina (Group-S), 36 patients were diagnosed with unstable angina (Group-U), and 37 patients had acute myocardial infarction (Group-A). Additionally, clinical data from 35 healthy individuals undergoing physical examination during the same time period were selected as the control group. Levels of blood lipid indicators and serum Lp-PLA2, IMA, and Cys-C levels were compared between the groups. RESULTS: The rates of diabetes, hypertension, and smoking in Group-S, Group-U, and Group-A were significantly higher than those in the control group (p<0.05). Levels of Lp-PLA2, IMA, and Cys-C in Group-S, Group-U, and Group-A were significantly higher than those in the control group (p<0.05). Levels of Lp-PLA2, IMA, and Cys-C in Group-U and Group-A were significantly higher than those in Group-S, and Group-A had the highest value of these indexes (p<0.05). Multivariate logistic regression analysis showed that Lp-PLA2, Cys-C, and IMA were important risk factors for the onset of CHD (p<0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of Lp-PLA2, IMA, and Cys-C predicting the occurrence of CHD was 0.775, 0.835, and 0.735, respectively. The combined prediction of the three factors has an AUC of 0.920, which is higher than the individual prediction. CONCLUSIONS: Lp-PLA2, IMA, and Cys-C are closely related to the onset and progression of CHD. These indicators, therefore, can be used in clinical practice to predict and evaluate CHD.

Homocysteine and Lp-PLA2 levels: Diagnostic value in coronary heart disease.

Coronary heart disease (CHD) is the leading cause of mortality worldwide. Identifying effective diagnostic markers and understanding risk factors is crucial for prevention and management. This study aimed to investigate the levels of homocysteine (Hcy) and lipoprotein-associated phospholipase A2 (Lp-PLA2) in human plasma and their roles in the diagnosis and prognosis of CHD. A retrospective study was conducted on 232 patients with CHD, divided into Acute Myocardial Infarction, unstable angina pectoris, and stable angina pectoris groups, and a control group of 75 healthy adults. Blood samples were analyzed for serum Hcy and Lp-PLA2 levels using the cycling enzyme method and ELISA method, respectively. Statistical analyses were performed to evaluate the risk factors, and diagnostic efficacy was assessed using receiver operating characteristic (ROC) curves. No significant differences in age and sex were observed between the study and control groups, whereas marked disparities in risk factors such as obesity, hypertension, diabetes, and hyperlipidemia were noted. Significant differences in serum Hcy and Lp-PLA2 levels were identified among the CHD subgroups. Univariate and multivariate logistic regression analyses revealed that Hcy, Lp-PLA2, hypertension, and hyperlipidemia were significant risk factors for CHD. The combined diagnostic Area Under the Curve (AUC) for Hcy and Lp-PLA2 was found to be higher than that when using them individually. This study identified the elevation of Hcy and Lp-PLA2 levels as independent risk factors for CHD, and their conjoint analysis significantly enhanced clinical diagnostic efficacy. These findings provide valuable insights for CHD diagnosis, treatment, and prevention, highlighting the importance of these markers in CHD management.

Risk factors for acute ischemic stroke in patients with type 2 diabetes mellitus.

To investigate the risk factors for acute ischemic stroke (AIS) in patients with type 2 diabetes mellitus (T2DM) patients. a total of 120 T2DM patients who met the inclusion and exclusion criteria, from between January 2021 to June 2022, were randomly selected and divided into T2DM and T2DM + AIS groups based on the presence or absence of a history of AIS. Blood samples were collected by fasting, 24 hours after admission, and levels of serum uric acid (UA), serum homocysteine (Hcy), serum creatinine (SCR), blood urea nitrogen (BUN), fasting blood glucose (FBG), glycated hemoglobin A1c (HbA1c), serum total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein (hs-CRP), and lipoprotein-associated phospholipase A2 (Lp-PLA2) were measured. Multivariate logistic regression analysis was performed for the significantly associated indicators to analyze the risk factors for AIS, and finally ROC curve analysis was carried out to explore the predictive value of the above risk factors for AIS in T2DM patients. the levels of FBG, Hcy, Hs-CRP and Lp-PLA2 were significantly higher in the T2DM + AIS group than those in T2DM group (P < .05). Multivariate logistic regression analysis revealed that hs-CRP and Lp-PLA2 were independent risk factors for the development of AIS in patients with T2DM with an OR of 2.85 (95% CI: 1.26-6.43, P = .012) and 3.64 (95% CI: 1.63-8.12, P = .002), respectively. ROC curve analysis showed that plasma hs-CRP and Lp-PLA2 showed good performance to predict AIS occurrence in T2DM patients (AUC = 0.749, 95% CI: 0.663, 0.835; and 0.791, 95% CI: 0.712, 0.870), with a sensitivity of 58.1% and 83.9%, and a specificity of 84.5% and 60.3%, respectively. The optimal concentration cutoff points of hs-CRP and Lp-PLA2 were 3.38 mg/L and 204.2 ng/mL. our findings suggested that plasma hs-CRP and Lp-PLA2 were independent risk factors for developing AIS in T2DM patients. Hs-CRP and Lp-PLA2 are potential biomarker for risk for AIS in patients with T2DM.

The association between circulating Hcy and Lp-PLA2 levels and poststroke depression: A meta-analysis.

OBJECTIVE: To analyze the correlation between circulating homocysteine (Hcy) and lipoprotein-associated phospholipase A2 (Lp-PLA2) levels and poststroke depression (PSD). MATERIALS AND METHODS: Chinese (Chinese National Knowledge Infrastructure, Wanfang, and VIP) and English (PubMed, EMBASE, MEDLINE, and Cochrane Library) databases on the correlation between circulating Hcy and Lp-PLA2 and PSD were collected. Meta-analysis was performed to compare the distinctions in circulating Hcy and Lp-PLA2 levels between PSD and non-PSD groups. Meta-analysis was conducted by using STATA 15.0 software. RESULTS: A total of 20 literatures were included in this study. The level of circulating Lp-PLA2 in the PSD group was obviously higher than that in the non-PSD group (weighted mean differences: 2.75, 95%CI: 0.10-5.39, P = .002), which was an independent predictor of PSD (effect size = 0.05, 95%CI: 0.03, 0.07, P < .001). The level of circulating Hcy in the PSD group was obviously higher than that in the non-PSD group (weighted mean differences = 1.41, 95%CI: 1.01, 1.81, P < .001), which was an independent influencing factor for the occurrence of PSD (effect size = 0.07, 95%CI: 0.04, 0.09, P = .011). CONCLUSION: Circulating Hcy and Lp-PLA2 levels are linked to the development of PSD, and can be applied as predictive or diagnostic indicators.

The lipoprotein-associated phospholipase A2 inhibitor Darapladib sensitises cancer cells to ferroptosis by remodelling lipid metabolism.

Arachidonic and adrenic acids in the membrane play key roles in ferroptosis. Here, we reveal that lipoprotein-associated phospholipase A2 (Lp-PLA2) controls intracellular phospholipid metabolism and contributes to ferroptosis resistance. A metabolic drug screen reveals that darapladib, an inhibitor of Lp-PLA2, synergistically induces ferroptosis in the presence of GPX4 inhibitors. We show that darapladib is able to enhance ferroptosis under lipoprotein-deficient or serum-free conditions. Furthermore, we find that Lp-PLA2 is located in the membrane and cytoplasm and suppresses ferroptosis, suggesting a critical role for intracellular Lp-PLA2. Lipidomic analyses show that darapladib treatment or deletion of PLA2G7, which encodes Lp-PLA2, generally enriches phosphatidylethanolamine species and reduces lysophosphatidylethanolamine species. Moreover, combination treatment of darapladib with the GPX4 inhibitor PACMA31 efficiently inhibits tumour growth in a xenograft model. Our study suggests that inhibition of Lp-PLA2 is a potential therapeutic strategy to enhance ferroptosis in cancer treatment.

Lipoprotein-Associated Phospholipase A2 has Comparable Ability as Anthropometric Indices to Discriminate Cardiovascular Disease Risk: A Cross-Sectional Study.

BACKGROUND AND AIM: Available evidence suggests that the indices of obesity may serve as good predictors of cardiovascular disease (CVD). This study compared the ability of lipoprotein-associated phospholipase A2 (Lp-PLA2) and anthropometric indices to discriminate CVD risk among the apparently healthy staff of Babcock University in Southwest Nigeria. METHODS: A descriptive cross-sectional study was conducted among apparently healthy staff. Participants' weight, height, body mass index (BMI), waist circumference (WC), hip circumference (HC), neck circumference (NC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), wrist circumference (WrC), and blood pressure were measured. Venous blood was collected for Lp-PLA2, lipid profile, and fasting plasma glucose (FPG) estimation. CVD risk was defined as the presence of either general obesity or abdominal obesity, diabetes mellitus, dyslipidaemia, hypertension or smoking. The receiver operating characteristic curve was used to compare the ability of LpPLA2 and the anthropometric indices to discriminate CVD risk in male and female participants. RESULTS: Results showed that 75.7% (106) of the participants had CVD risk. Anthropometric indices (weight, BMI, WC, HC, NC, WrC, WHR, and WHtR), FPG, lipid profile and Lp-LPA2 were higher among participants with CVD risk (p<0.05). Among the men, LpPLA2 had the largest area under the curve (AUC) (AUC= 0.886, p<0.001), closely followed by BMI (AUC = 0.879, p<0.001), WC (AUC = 0.864, p<0.001), and WHtR (AUC= 0.866, p<0.001). Among the women, WHtR had the largest AUC of 0.995 (p<0.001), followed by WC (AUC = 0.990, p<0.001), BMI (AUC = 0.970, p<0.001), and Lp-PLA2 (AUC= 0.938, p<0.001). CONCLUSION: The abilities of Lp-PLA2 and anthropometric indices to predict CVD risk are comparable among the male and female apparently healthy staff of a private tertiary university in Southwest Nigeria. CONTEXTE ET OBJECTIF: Les données disponibles suggèrent que les indices d'obésité peuvent servir de bons prédicteurs des maladies cardiovasculaires (MCV). Cette étude a comparé la capacité de la phospholipase A2 associée aux lipoprotéines (Lp-PLA2) et des indices anthropométriques à discriminer le risque de MCV parmi le personnel apparemment en bonne santé de l'Université Babcock, dans le sud-ouest du Nigeria. MÉTHODES: Une étude descriptive transversale a été menée auprès de membres du personnel apparemment en bonne santé. Le poids, la taille, l'indice de masse corporelle (IMC), le tour de taille (WC), le tour de hanches (HC), le tour de cou (NC), le rapport taille-hanche (WHR), le rapport taille-hauteur (WHtR), le tour de poignet (WrC) et la pression artérielle des participants ont été mesurés. Du sang veineux a été prélevé pour mesurer la Lp-PLA2, le profil lipidique et la glycémie à jeun. Le risque de MCV a été défini comme la présence d'une obésité générale ou d'une obésité abdominale, d'un diabète sucré, d'une dyslipidémie, d'une hypertension ou d'un tabagisme. La courbe caractéristique du récepteur a été utilisée pour comparer la capacité de la Lp-PLA2 et des indices anthropométriques à discriminer le risque de MCV chez les hommes et les femmes. RÉSULTATS: Les résultats ont montré que 75,7 % (106) des participants présentaient un risque de MCV. Les indices anthropométriques (poids, IMC, tour de taille, HC, NC, WrC, WHR et WHtR), la glycémie, le profil lipidique et la Lp-LPA2 étaient plus élevés chez les participants présentant un risque de MCV (p<0,05). Chez les hommes, la Lp-PLA2 présentait la plus grande aire sous la courbe (AUC) (AUC = 0,886, p<0,001), suivie de près par l'IMC (AUC = 0,879, p <0,001), le tour de taille (AUC = 0,864, p <0,001) et le WHtR (AUC = 0,866, p <0,001).Chez les femmes, le WHtR présentait la plus grande aire sous la courbe de 0,995 (p<0,001), suivi du tour de taille (aire sous la courbe de 0,990, p<0,001), de l'IMC (aire sous la courbe de 0,970, p<0,001) et de la LpPLA2 (aire sous la courbe de 0,938, p<0,001). CONCLUSION: Les capacités de Lp-PLA2 et des indices anthropométriques à prédire le risque de MCV sont comparables parmi le personnel masculin et féminin apparemment en bonne santé d'une université tertiaire privée du sud-ouest du Nigeria. Mots-clés: Phospholipase A2 associée aux lipoprotéines, indices anthropométriques, risque cardiovasculaire, Nigeria.

The diagnostic value of lipoprotein-associated phospholipase A2 in early diabetic nephropathy.

OBJECTIVE: The aim of this study was to investigate diagnosis of lipoprotein-associated phospholipase A2 (Lp-PLA2) in early diabetic nephropathy (DN). METHODS: A total of 342 type 2 diabetes mellitus (T2DM) patients hospitalized in department of metabolism and nephrology in our hospital from January 2019 to December 2019 were randomly selected. Patients were divided into three groups via urine albumin level: diabetes mellitus (DM) group, simple diabetes group (114 patients, urinary albumin creatinine ratio (UACR) < 30 mg/g); DN1 group, early DN group (114 patients, UACR: 30-300 mg/g); DN2 group: clinical DN group (114 patients, UACR > 300mg/g). Eighty healthy adults were examined at the same time. Lp-PLA2, fasting blood glucose (FBG), creatinine (Cr), triglyceride (TG), total cholesterol (TCHOL), high-density lipoprotein (HDL), low-density lipoprotein (LDL), haemoglobin A1c (HbA1c), blood urea nitrogen/creatinine (BUN/Cr), estimated glomerular filtration rate (eGFR), 24-h urine protein, albumin and creatinine of all subjects were detected and compared. Pearson's correlation analysis and multiple ordered logistic regression were used to investigate the correlation between serum Lp-PLA2 level and DN. The possibility of Lp-PLA2 in the diagnosis of early DN was studied by using the subject working curve. RESULTS: Lp-PLA2 level in DN1 and DN2 groups was significantly higher than that in DM group, with statistical difference (p < .05). With the progression of DN, the level of Lp-PLA2 gradually increased p < .05. Lp-PLA2 was positively correlated with FBG, TG, LDL and HbA1c (R = 0.637, p < .01; R = 0.314, p = .01; R = 0.213, p = .01; R = 0.661, p ≤ .01), was negatively correlated with HDL (r = -0.230, p < .01). The results showed that Lp-PLA2 was an independent factor in the evaluation of early DN. The area under the curve for the evaluation of serum Lp-PLA2 level in early DN was 0.841, the optimal critical value was 155.9 ng/mL, the sensitivity was 88% and the specificity was 76.2%. CONCLUSIONS: Lp-PLA2 is an independent factor for the evaluation of early DN, and can be used as an important potential specific indicator for the diagnosis of early DN, meanwhile monitoring the progression of DN.

Lp-PLA2 silencing ameliorates inflammation and autophagy in nonalcoholic steatohepatitis through inhibiting the JAK2/STAT3 pathway.

Background: Nonalcoholic steatohepatitis (NASH), a common cause of liver-related morbidity and mortality worldwide, is characterized by inflammation and hepatocellular injury. Our research focuses on lipoprotein-associated phospholipase A2 (Lp-PLA2), an inflammation-related biomarker that has recently garnered interest in the context of NASH due to its potential roles in disease pathogenesis and progression. Methods: We established a NASH mouse model using a high-fat diet (HFD) and treated it with sh-Lp-PLA2 and/or rapamycin (an mTOR inhibitor). Lp-PLA2 expression in NASH mice was detected by qRT-PCR. Serum levels of liver function parameters and inflammatory cytokines were detected using corresponding assay kits. We examined pathological changes in liver using hematoxylin-eosin, oil red O, and Masson staining, and observed autophagy through transmission electron microscopy. The protein levels of Lp-PLA2, mTOR, light chain 3 (LC3) II/I, phosphorylated Janus kinase 2 (p-JAK2)/JAK2, and phosphorylated signal transducer and activator of transcription 3 (p-STAT3)/STAT3 were determined by western blotting. Kupffer cells extracted from C57BL/6J mice were treated to replicate NASH conditions and treated with sh-Lp-PLA2, rapamycin, and/or a JAK2-inhibitor to further verify the roles and mechanisms of Lp-PLA2 in NASH. Results: Our data indicate an upregulation of Lp-PLA2 expression in HFD-induced NASH mice. Silencing Lp-PLA2 in NASH mice reduced liver damage and inflammation markers (aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), triglycerides (TG), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6)), while increasing IL-10 levels, an anti-inflammatory cytokine. Additionally, Lp-PLA2 silencing decreased lipid and collagen accumulation and promoted autophagy. The beneficial effects of sh-Lp-PLA2 on NASH were enhanced by rapamycin. Furthermore, Lp-PLA2 silencing resulted in the downregulation of the expression of p-JAK2/JAK2 and p-STAT3/STAT3 in NASH mice. Similar results were observed in Kupffer cells treated under NASH conditions; Lp-PLA2 silencing promoted autophagy and repressed inflammation, effects which were potentiated by the addition of rapamycin or a JAK2-inhibitor. Conclusion: Our findings suggest that silencing Lp-PLA2 promotes autophagy via deactivating the JAK2/STAT3 signaling pathway, thereby restraining NASH progression. This highlights the potential therapeutic value of targeting Lp-PLA2, adding a new dimension to our understanding of NASH pathogenesis and treatment strategies.

Novel Electrochemiluminescent Immunosensor Using Dual Amplified Signals from a CoFe Prussian Blue Analogue and Au Nanoparticle for the Detection of Lp-PLA2.

Coronary heart disease (CHD) poses an important threat to human health, and its pathogenesis is the formation of atheromatous plaques in coronary ventricles. Compared to other biomarkers, lipoprotein-associated phospholipase A2 (Lp-PLA2), which is involved in multiple processes of atherosclerosis, is a noticeable inflammatory biomarker related to CHD. Herein, using a multifunctional nanocomposite containing a CoFe Prussian blue analogue (PBA) and Au nanoparticles (AuNPs) (AuNPs@CoFe PBA) as a sensing substrate, an electrochemiluminescent (ECL) immunosensor was developed for the highly sensitive detection of Lp-PLA2. Benefiting from the synergistic effect of the PBA and AuNPs, the nanocomposite exhibits excellent peroxidase-like activity and can catalyze the luminol-ECL reaction, amplifying the ECL signal by ∼29-fold. Meanwhile, the enlarged specific surface area of the nanocomposite and the presence of abundant AuNPs allow the immobilization of more antibody proteins, thereby improving the sensing response of the immunosensor. When the target Lp-PLA2 is captured by the antibody on the sensor surface, the sensor emits a reduced ECL signal because of the increased mass and electron transfer resistance due to the formation of the immune complex. Under optimized conditions, the constructed ECL immunosensor exhibits a broad linear range from 1 to 2200 ng/mL and a low detection limit of 0.21 ng/mL. Additionally, the ECL immunosensor exhibits high specificity, stability, and reproducibility. This work provides a new approach to diagnose CHD and broadened the application of the PBA in the field of ECL sensors.

The value of serum Lp-PLA2 combined with MPO in the diagnosis of cerebral infarction caused by large artery atherosclerosis.

OBJECTIVE: To explore the value of serum lipoprotein-associated phospholipase A2（Lp-PLA2）combined with myeloperoxidase（MPO）for the diagnosis of large artery atherosclerosis(LAA) cerebral infarction. METHODS: Baseline data were collected from patients with first-ever acute cerebral infarction, serum Lp-PLA2 and MPO levels were measured. The etiology of cerebral infarction was classified according to the Chinese Ischemic Stroke Subtype Classification Standard. The risk factors associated with LAA cerebral infarction were identified by univariate and multivariate regression analysis. The diagnostic value of serum Lp-PLA2 and MPO for LAA cerebral infarction was assessed by the area under the receiver-operating characteristic (ROC) curve. RESULTS: Overall 368 patients were involved, 148 patients (40.22 %) were LAA. The serum La-PLA2 and MPO levels were higher in the LAA group than those in non-LAA group (23.06 ± 3.39 ng/mL versus 17.48 ± 3.26 ng/mL; 93.60 ± 9.58 ng/mL versus 75.98 ± 15.53 ng/mL; P < 0.001 for both). Multivariate analysis showed that elevated levels of serum Lp-PLA2 (OR 1.742, 95 %CI 1.499-2.025; P < 0.001) and MPO (OR 1.060, 95 % CI 1.026-1.096; P = 0.001) were the independent risk factors of LAA cerebral infarction. The area under curve of the serum Lp-PLA2 combined with MPO for the diagnosis of LAA cerebral infarction was 0.896 [0.866 ∼ 0.927] (P < 0.001). CONCLUSION: Serum Lp-PLA2 combined with MPO could be valued as a predictor of acute cerebral infarction caused by large artery atherosclerosis.